Guitar String Tension Calculator

Guitar string tension determines how a string feels to play and how it affects your guitar’s neck. Understanding tension helps you choose the right string gauge for your playing style and instrument.

The Physics: String tension is governed by the vibrating string equation. For a string of a given length, tuned to a specific frequency, tension depends on the string’s mass per unit length.

Simplified formula for plain steel strings: T = UW × (2 × L × f)²

Where:

• T = tension in pounds
• UW = unit weight (mass per unit length, approximated as gauge² × 0.000386 for plain steel)
• L = scale length in inches
• f = frequency in Hz

Common scale lengths:

• 25.5 inches: Fender Stratocaster, Telecaster (standard “long scale”)
• 25 inches: Paul Reed Smith (PRS)
• 24.75 inches: Gibson Les Paul, SG, ES-335 (“short scale”)
• 24 inches: Some vintage Gibsons, short-scale bass guitars

Standard E tuning frequencies (Hz):

Typical tension values for standard gauge sets on a Strat (25.5"):

Most players find 14–20 lbs per string comfortable. Below 10 lbs feels very slack; above 25 lbs feels very stiff. Total set tension (6 strings) on a Strat with .010–.046 gauge is typically around 105–115 lbs. This total tension directly affects neck relief — heavier gauge strings require more neck relief or truss rod adjustment.